Submit A Form Without Page Refresh using jQuery

Previously on Nettuts+, Philo showed how you can use jQuery to add form validation to wordpress comments that works without any page reload. Another great way of utlizing jQuery to enhance user experience is to not just validate, but to submit your form entirely without a page refresh.

In this tutorial I'll show you how easy it is to do just that -- submit a contact form that sends an email, without page refresh using jQuery! (The actual email is sent with a php script that processes in the background). Let's get started.

What We're Building

In this example, we have a simple contact form with name, email, and phone number. The form submits all the fields to a php script without page refresh, using native jQuery functions (native meaning, you don't need to download any extra plugins to make it work.

You might notice that I have included a div with id contact_form that wraps around the entire form.
Be sure to not miss that div in your own form as we will be needing this wrapper div later on. You
might also notice that I have left both the action and the method parts of the form tag blank. We
actually don't need either of these here, because jQuery takes care of it all later on.

Another important thing to be sure to include is the id values for each input field. The id values
are what your jQuery script will be looking for to process the form with.

I've added some css styles and a background image in Photoshop to produce the following form:

What the first function() does is, it loads the events inside, as soon as the html document is ready. If you have done any work in jQuery previously, the function is the same as jQuery's document.ready function. So we start with that, and inside we have our click function that executes on clicking the submit button with class name of "button". Ultimately what we have accomplished with these lines of code is the same as if we were to add an onclick event to the submit button in the html. The reason we do it with jQuery is for clean separation of our presentation from our scripts.

Inside our function that loads when the page is ready, we add some form validation. But the first thing you see that got added is $('.error').hide();. What this does is hides our 3 labels with class name "error". We want these labels to be hidden not just when
the page first loads, but also when you click submit, in case one of the messages was shown to the user previously. Each error message should only appear if validation doesn't work out.

We validate by first checking if the name field was left blank by the user, and if it is, we then show the label with id of name_error. We then place the focus on the name input field, in case the user
is at all confused about what to do next! (I have learned to never assume too much when it comes to form users).

To explain in more detail how we are making this happen, we set a variable 'name' to the value of the input field with id "name" -- all with one line of jQuery:

var name = $("input#name").val();

We then check if that value is blank, and if it is, we use jQuery's show() method to show the label with
id "name_error":

if (name == "") {
$("label#name_error").show();
}

Next, we place the form focus back on the input field with id of "name", and finally return false:

Be sure to have return false in your code, otherwise the whole form gets submitted (which defeats
the purpose of this tutorial)! What return false does is it prevents the user from proceeding any further
without filling out the required field(s).

Step 4 - Process our Form Submission with jQuery's AJAX Function

Now we get to the heart of the tutorial -- submitting our form without page refresh, which sends the form values to a php a script in the background. Let's take a look at all the code first, then I will break down into more detail next. Add the following code just below the validation snippet we added previously (and before the button click function is closed out):

We have a lot going on here! Let's break it all down - it's so simple and so easy to use once you understand the process. We first create a string of values, which are all the form values that we want to pass along to the script that sends the email.

Recall previously, we had set a variable 'name' with the value of the input field with id "name", like so:

var name = $("input#name").val();

We can use that 'name' value again, as well as the 'email' and the 'phone' values, to create our dataString:

I've commented out an alert that I sometimes use to be sure I am grabbing the right values, which you may find helpful in the process. If you uncomment that alert and test your form, assuming everything has gone right so far, you should get a message similar to the following:

Now we get to our main ajax function, the star of today's show. This is where all the action happens, so pay
close attention!

Basically what's going on in the code is this: The .ajax() function processes the values from our string called dataString (data:dataString) with a php script called process.php (url:"bin/process.php"), using the 'POST' method (type:"POST"). If our script processed successfuly, we can then display a message back to the user, and finally return false so the page does not reload. That's it! The entire process is handled right there in these few lines!

There are more advanced things you can do here, other than sending an email and giving a success message. For example you could send your values to a database, process them, then display the results back to the user. So if you posted a poll to users, you could process their vote, then return the voting results, all without any page refresh required.

Let's summarize what happened in our example, to be sure we have covered everything. We grabbed our form values with jQuery, and then placed those into a string like this:

Then we used jQuery's ajax function to process the values in the dataString. After that
process finishes successfully, we display a message back to the user and add return false so that our page does not refresh:

The success part of the script has been filled in with some specific content that can be displayed back to the user. But as far as our ajax functionality goes, that's all there is to it. For more options and settings be sure to check out jQuery's documentation on the ajax function. The example here is one of the simpler implementations, but even so, it is very powerful as you can see.

Step 5 - Display a Message Back to the User

Let's briefly look at the part of the code that displays our message back to the user, to finish out the tutorial.

First, we change the entire contents of the contact_form div (remember I said we would be needing that div) with the following line:

$('#contact_form').html("<div id='message'></div>");

What that has done is replaced all the content inside the contact_form div, using jQuery's html() function. So instead of a form, we now just have a new div inside, with id of 'message'. Next, we fill that div with an actual message -- an h2 saying "Contact Form Submitted":

$('#message').html("<h2>Contact Form Submitted!</h2>")

We next add even more content to the message div with jQuery's append() function, and to top everything off we add a cool effect by hiding the message div with the jQuery hide() function, then fade it all in with the fadeIn() function:

By now, I think you will have to agree that it is incredibly easy to submit forms without page refresh using jQuery's powerful ajax function. Just get the values in your javascript file, process them with the ajax function and return false, and you are good to go. You can process the values in your php script just like you would any other php file, the only difference being that the user does not have to wait for a page refresh - it all happens silently in the background.

So if you have a contact form on your website, a login form, or even more advanced forms that process values through a database and retrieve results back, you can do it all easily and efficiently, and perhaps most importantly, you enhance the end user experience with your website by providing interactivity without their having to wait for the page to reload.

Conclusion

I would like to add some final words about the demo example provided. In the demo, you may notice that there is in fact one plugin being used - the runonload.js file. I did state at the beginning of the tutorial that we would not be using any plugins, and then you find in the demo there is an extra runonload script, so some explanation may be necessary! For anyone interested in seeing a live working demo, you can view my website's SEO consulting form.

The only use I made with runonload actually has nothing to do with processing the form. So you can accomplish the ajax functions completely without any extra plugins. I only used runonload to focus the name input field on page load. It has been my experience that calling runonload can sometimes be a better replacement for jQuery's native document ready function, and I found that to be the case while putting together this tutorial. For some reason the focus() function would not work on page load using jQuery's native document ready function -- but it did work with runonload, and that is why you find it as part of the example. So if you know of a way to accomplish that without using runonload I would be happy to hear from you about that.